The invention relates to a method of manufacturing a flat, glass-like or ceramic moulding having a structured surface.
It is known that glass-like or ceramic mouldings can be manufactured from a suspension of a finely dispersed, powder-ceramic material. In the known process, first a moist, still shapable green body is manufactured which is not ready for use until after the subsequent drying and sintering processes. This method has the advantage that shaping takes place at room temperature. The solids content in the pre-densified green body should be as high as possible to minimize shrinkage during drying and sintering.
In German Offeniegungsschrift 37 02 025, a description is given of the manufacture of rotationally symmetrical, porous solid bodies having a high relative density from a diluted suspension which contains SiO.sub.2 particles as the powder-ceramic material, in which process centrifugal forces are used to successively deposit thin films of solid particles by centrifuging in a hollow mould. The mouldings thus formed have a tubular geometry.
It has also been proposed to further densify the green bodies manufactured by the above rotation process by subjecting said green bodies to an ultrasonic liquefaction process and to yet another centrifuging process. This enables a second, much more densified, moist green body to be manufactured, whose solids content can be further increased by repeating the above-mentioned post-densification steps.
Many applications require, however, flat, glass-like or ceramic mouldings which are provided with a structure which is adapted to the intended application. If, for example, a quartz-glass disc having a specific surface profile or apertures is required, special etch or drill processes must be carried out by means of the appropriate, expensive equipment. Such flat glasses are necessary, for example, for flat display screens, printing heads (Bubble Jet, Ink Jet), optical filters which can withstand high thermal loads, as well as microlenses.